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| author | Jesper Dangaard Brouer <brouer@redhat.com> | 2017-08-17 18:22:37 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-08-18 16:18:40 -0700 |
| commit | 4c03bdd7b5c084c3c6973cb2419edac5363c051f (patch) | |
| tree | 77e091a3b5de3c55433947ec41891ba2b1e52019 /net | |
| parent | d2cee2e5d0106abb5da25f393b3c50e0bb01f7f9 (diff) | |
| download | linux-4c03bdd7b5c084c3c6973cb2419edac5363c051f.tar.gz linux-4c03bdd7b5c084c3c6973cb2419edac5363c051f.tar.bz2 linux-4c03bdd7b5c084c3c6973cb2419edac5363c051f.zip | |
xdp: adjust xdp redirect tracepoint to include return error code
The return error code need to be included in the tracepoint
xdp:xdp_redirect, else its not possible to distinguish successful or
failed XDP_REDIRECT transmits.
XDP have no queuing mechanism. Thus, it is fairly easily to overrun a
NIC transmit queue. The eBPF program invoking helpers (bpf_redirect
or bpf_redirect_map) to redirect a packet doesn't get any feedback
whether the packet was actually transmitted.
Info on failed transmits in the tracepoint xdp:xdp_redirect, is
interesting as this opens for providing a feedback-loop to the
receiving XDP program.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/filter.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 0f4df86d936a..fa2115695037 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2535,14 +2535,16 @@ int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp, struct bpf_map *map = ri->map; u32 index = ri->ifindex; struct net_device *fwd; - int err = -EINVAL; + int err; ri->ifindex = 0; ri->map = NULL; fwd = __dev_map_lookup_elem(map, index); - if (!fwd) + if (!fwd) { + err = -EINVAL; goto out; + } if (ri->map_to_flush && (ri->map_to_flush != map)) xdp_do_flush_map(); @@ -2552,7 +2554,7 @@ int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp, ri->map_to_flush = map; out: - trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT); + trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err); return err; } @@ -2562,6 +2564,7 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, struct redirect_info *ri = this_cpu_ptr(&redirect_info); struct net_device *fwd; u32 index = ri->ifindex; + int err; if (ri->map) return xdp_do_redirect_map(dev, xdp, xdp_prog); @@ -2570,12 +2573,14 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, ri->ifindex = 0; if (unlikely(!fwd)) { bpf_warn_invalid_xdp_redirect(index); - return -EINVAL; + err = -EINVAL; + goto out; } - trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT); - - return __bpf_tx_xdp(fwd, NULL, xdp, 0); + err = __bpf_tx_xdp(fwd, NULL, xdp, 0); +out: + trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err); + return err; } EXPORT_SYMBOL_GPL(xdp_do_redirect); |